Locking device in shelf stands

ABSTRACT

A device in shelf stands with several shelves  3  with sloping storage trays  4  which are extendable on a holder arm  5  in order to facilitate replenishing and removing goods stored in the trays. The trays  4  secured in the retracted position by means of a locking device which is operated from the front side of the trays.  
     The locking device comprises a leaf-shaped locking hook  9, 15  which when the tray is extended moves in a channel  10, 16  arranged in the upper or under side of the tray.  
     At the arid facing the back side of the tray the locking hook is connected to a pivot  13, 13   a  in the holder  5  and at the other end, when the tray  4  is retracted to its position of application extends from the channel  10, 16  with a hook-shaped part  14, 19  which is arranged to cooperate with a locking plate  12, 18  on the front edge of the tray which engages the hook-shaped part  14, 19  of the locking hook  9, 15.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to Swedish Patent Application No.0501976-5, filed on Sep. 7, 2006, the entire disclosure of which ishereby incorporated by reference in its entirety herein.

DESCRIPTION

The present invention relates to a device in shelf stands with severalshelves with sloping storage trays or shelves which are extendable on aholder arm in order to facilitate replenishing and removing goods storedin the trays, whereby the trays are secured in the retracted position bymeans of a locking device which is operated from the front side of thetrays.

Such a shelf stand is disclosed in the Swedish Patent No. 449293,wherein several circlesector-shaped, extendable shelves or trays arecarried on arms extending from a central column so that the trays formcircular shelf arranged to slope slightly downwards. The trays areprovided with locking means locking them in retracted and extendedposition respectively.

Thereby it is desired that the distance between the shelves does notappreciably exceed the height of the goods which shall be stored on theshelves so that the total height of the shelf stand is as small aspossible. A problem is to accomplish a locking device which does notintrude on the distance between the shelvs but still enables operatingthe locking device from the front side of the trays.

The object of the invention is to accomplish a locking device whichsolves said problem and this object is achieved by a locking devicewhich according to the invention obtains the characteristic featuresdefined in the following claims.

The invention will be disclosed in greater detail with reference toembodiments illustrated in the drawings.

FIG. 1 shows an example of a shelf stand of known art in which a lockingdevice according to the invention may be used.

FIG. 2 shows a plan view of a shelf of the stand shown in FIG. 1.

FIG. 3 shows a perspective, cross section through the central part of anextendable tray of the stand, the tray being provided with a lockingdevice according to the invention.

FIG. 4 shows on a larger scale a side view of the locking device shownin FIG. 3 and in activated state.

FIG. 5 shows on a larger scale a cross section along the line V-V inFIG. 4.

FIG. 6 shows a perspective, cross section like FIG. 3 through thecentral part of an extendable tray with another kind of locking deviceaccording to the invention.

FIG. 7 shows on a larger scale a perspective, side view of the lockingdevice in FIG. 6.

FIG. 9 shows on a larger scale a cross section along the line VIII-VIIIin FIG. 7.

The shelf stand shown in FIG. 1 comprises a central column 1 which issupported by a base or foot 2. The central column 1 carries several oneabove the other situated shelves 3 which are individually rotatableround the column 1.

Every shelf consists of several essentially circlesector-shaped shelfsections or trays 4 extendable on arms 5 extending from a holder 6rotatably arranged on the central column 1. The trays are provided witha sleeve-like part 7 which is telescopically placed over thecorresponding arm 5 and carried on a support wheel 8 (FIG. 4) so thatthe tray 4 may be moved between an entirely retracted and an extendedposition. The arms 5 are sloping downwards so that the goods on theshelf glide down against the front side without the necessity to extendthe tray. If that does not happen or goods are being refilled on theshelf it is necessary to he able to extend the tray, see FIG. 2 in whicha tray 4 is shown extended. The extension of the trays 4 in the stand islimited in a way known per se e.g. by a stop screw arranged on the arms5 which screw moves in a slit in the sleeve 7 of the tray 4 (not shown).

Since the trays are sloping a locking device easily operated from theouter edge of the tray must in the retracted position secure the trays.Known securing means have been arranged at the back edge of the trayfacing the holder 6 and this securing means has been operated by meansof an uncovered arm arranged below the tray 4 which arm has an effect onthe space between the trays.

Instead, according to this invention, an elongated leaf-shaped lockingarm or hook 9 is provided which is shown in FIG. 3-5 and which extendsin a channel 10 formed on the upper side of the tray 4 which channel isconnected to the sleeve 7 and is formed by an inverted U-shaped sheet 11which is fastened such as welded to the upper face of the tray's 4bottom essentially centrally in the tray. The channel 10 is just so muchwider than the thickness of the securing hook 9 that this with littleplay to the sides of the channel 10 can move freely in the channel,while a greater play vertically allows the locking hook 9 to be broughtin and out of engagement with a locking plate 12 on the front side ofthe tray 4. To this end the locking hook 9 is at its inner end carriedon a pivot 13 fastened to the inner end of the arm 5 so that the lockinghook can swing upwardly when the outer hook-shaped part of the lockinghook 9 catch hold over the plate 12 and locks the tray 4 in retractedposition. The outer end of the locking hook 9 is to this end rounded sothat the locking hook 9 is lifted when it strikes the sheet 12 and bygravity falls down with a notch 14 over the plate 12.

In the embodiment according to FIG. 6-8 a securing hook 15, which withan upturned part 15 a is carried on a pivot 13 a on the arm 5corresponding to the pivot 13 in FIG. 4, is arranged flat against theunderneath side of the tray 4 in a channel 16 which is formed by aU-shaped plate 17 fastened such as welded to said underneath side herealso essentially centrally in the tray. In this case only a small playexists between the securing hook 15 and the sides of the channel 16since the hook 15 shall only be freely moveable in the longitudinaldirection of the channel 16 when the tray 4 is extended. The tray 4 isthus locked in the retracted position by a lockbolt 20 fastened at thefront side of the tray which by means of a turned part 18 engages anotch 19 in the hook 15 when the tray is retracted. The lockbolt 20 ismade of a resilient material and is biased against the locking positionshown but can be removed from engagement with the notch 19 of the hook15 by an operating arm 21 when the tray 4 shall be extended.

It is obvious from the above that the embodiment with a leaf-shapedlocking hook 9, 15 which is kept in a. narrow channel 10, 16 above orunder the tray 4 does not build upon the height of the tray but thedistance between the shelves 3 may be adapted entirely to the height ofthe goods which is to be stored on the shelves.

When the trays 4 shall be extended e.g. for replenishing goods thelocking hook 9 is lifted from engagement with the plate 12, see FIG. 4,or the lockbolt 20 is brought from engagement with the notch 19, seeFIG. 7, so that the tray is released When the trays 4 again areretracted the locking hook 9 and 15 respectively comes into engagementwith the locking plate 12 and the lockbolt 20 respectively so that thtrays are locked in their normal application positions. By the lockingdevices being situated at the front edge of the trays the function willbe simple and safe.

It is obvious that the invention is not limited to the disclosedembodiments but can be altered in order to adapt the locking device toshelf stands and trays other than those shown.

1. A device in shelf stands with several shelves with sloping storagetrays which are extendable on a holder arm in order to facilitatereplenishing and removing goods stored in the trays, whereby the traysare secured in the retracted position by means of a locking device whichis operated from the front side of the trays, characterized in that thelocking device comprises a leaf-shaped locking hook which when the trayis extended moves in a channel arranged in the upper or under side ofthe tray and which at the end facing the back side of the tray isconnected to a pivot in the holder arm and at the other end, when thetray is retracted, extends from the channel with hook-shaped part whichis arranged to cooperate with a locking plate on the front edge of thetray and which is arranged to engage with force in the hook-shaped partof the locking hook.
 2. A device according to claim 1, characterized inthat the locking hook extends in a channel formed by a U-shaped sheetfastened to the upper or under side of the tray.
 3. A device accordingto claim 2, characterized in that the locking hook is rotatablyconnected to the pivot and that the U-shaped channel has such heightthat th locking hook can be lifted over and engage a locking plate onthe forward edge of the tray.
 4. A device according to claim 2,characterized in that the locking hook is arranged with little play inthe channel and arranged to cooperate with a locking plate rotatablyarranged on the forward edge of the tray which plate engages thehook-shaped part of the locking hook when the tray is retracted.
 5. Adevice according to claims 1, 2, 3, or 4, characterized in that theengagement between the locking hook and the locking plate is by means ofgravity or spring force.